Technical Abstract:
The Automated Multiple Pass Method (AMPM) Blaise instrument, developed by the Food Surveys Research Group, Agricultural Research Service, U.S. Department of Agriculture, collects 24-hour dietary recall data. During the interview, respondents recall the foods and beverages that were consumed the day before the interview. Details describing the types of foods and beverages are collected as well as an estimate of the portions consumed. These details are used to assign food codes and calculate gram weights and nutrients for the reported foods.
There are more than 2,500 questions and more than 21,000 responses in the AMPM instrument. Each question is represented by a unique field name. Open-ended responses are limited by the use of over 90 look-up tables, resulting in standardized responses. The unique combination of field names and responses creates a pathway that describe a particular food. The number of possible pathways through all the food detail questions is estimated to be over 400,000. To identify the most frequently reported pathways, we analyzed approximately 147,000 foods that had been reported using the AMPM instrument and coded manually by trained food coders. From this data set, a database of approximately 12,000 pathways linked to food codes was created. Complex pathways that required multiple food codes and pathways containing open-ended responses were excluded from this database. Pathways were grouped by food category and assigned a unique path number. The most common pathways were reviewed by a nutritionist, ensuring that the correct food code was linked to the pathway. Once the pathways are approved as correct, they are incorporated into the Post Interview Processing System (PIPS) where they are used to automatically code food intake data collected with the AMPM. Currently, PIPS is able to autocode approximately 48% of reported foods using 1,877 reviewed pathways linked to 964 foods.